Analog instruments in motor vehicles for indicating speed or fuel level, for example, generally use a gauge comprising an electrically driven armature which moves a pointer across a dial. An electrical signal proportional to the parameter measured ideally drives the pointer to an angular position representing the parameter. Hysteresis in the gauge causes a lag in the gauge movement so that actual pointer position falls short of the ideal position. As the signal changes in a manner to change direction of the pointer, the pointer reverses at a turn-around point to move in the new direction.
An arrangement for correcting for hysteresis uses a dual table approach; a table for each direction of motion alters the gauge motion. The problem with that approach is that the gauge jumps at turn-around points because the two tables are too far apart, or there is insufficient correction away from turn-around points because the tables are too close together. Another arrangement adds a fixed increment of movement in the current direction. The problem here is that it causes jumps at turn-around points because the increment is too large, or there is insufficient correction away from turn-around points because the increments are too small.
It is therefore desirable to correct gauge movement in a manner which eliminates gauge jumps at the turn-around points and improves accuracy at regions far from the turn-around points.